So I've owned my Accord (cd5) for about a year and a couple months now. It's seen a life before and came with a F20B bottom end with the F22 SOHC head installed. It ran great and drove great until my cat clogged and caused a slew of problems ever since. Anyways, recently I noticed a very very light knock at acceration. I have an exhaust so I can't hear my motor constantly but I can definitely hear it as soon as I accelerate and then put my clutch in I can hear it lightly and when I rev it sounds intermediate and only makes the knock for a few seconds before it stops and drives like normal. I thought I may have had a lightly bent valve as after my cat clogged I jumped a tooth in timing and did a new timing kit and it seemed to run fine but rich, I dealt with it as this is my only car and my first car but knew not to push it too hard so here I am. Not pushing it anymore because I don't want to blow my motor and at least have something somewhat salvagable in the end. Please help.